In the related art, switches (hereinafter referred to as “TSWs”) for performing switching in time division multiplexing (TDM) communication have been proposed. In a TSW, the ratio of the number of input slots, the number of slots to be replaced in the TSW, and the number of output slots was 1:1:1. In other words, it was necessary to prepare slots to be replaced in the TSW and internal circuits according thereto which correspond in number to a multiple of the number of input and output slots in a main module that consolidates TDM communication lines.
Further, techniques related to TSWs are disclosed in Patent Document 1 and Patent Document 2. Patent Document 1 discloses a technique of reducing the circuit size such that an output multiplexing circuit sequentially selects outputs from a data memory, multiplexes the outputs, and outputs output multiplexing time division data to an output highway. Further, Patent Document 2 discloses a technique of controlling a multiplicity converting circuit in a digital exchange such that the number of call channels needed by each line interface unit is displayed and read by a control unit.